a = [(4,6),(1, 3), (2, 2)]
print(sorted(a,key=lambda x:(x[1])))
print(5//2)
a='aa'
gg = "flow"
gg = gg[::-1]
gong = 'fl'
gong = gong[::-1]
print(a[:2])
print(gg.endswith(gong))